Fix sending smm option to qemu

Fix #689

tests/modules/qemu/test_qemu_vm.py

@@ -481,7 +481,8 @@ def test_build_command_kvm_2_4(linux_platform, vm, loop, fake_qemu_binary, port_
             "-smp",
             "cpus=1",
             "-enable-kvm",
-            "-machine smm=off",
+            "-machine",
+            "smm=off",
             "-boot",
             "order=c",
             "-serial",